Conventionally, a terminal connector that is connected to an end of an electric wire disclosed in Patent Document 1 is known as an example of such a kind. The terminal connector is formed by pressing a metal plate material and comprises a crimping portion that is crimped onto a core wire exposed from an end of an electric wire.
An oxide layer is formed on a surface of the core wire, and the oxide layer is interposed between the core wire and the crimping portion. This may increase a contact resistance between the core wire and the crimping portion.
In the prior art, recesses (serrations) are formed on an inner side (a side closer to the core wire) of the crimping portion. The recesses are continuously extended in a direction crossing to an extending direction of the electric wire. A plurality of recesses are aligned along the extending direction of the electric wire and formed by pressing a metal plate material with a die.
When the crimping portion is crimped onto the core wire of the electric wire, the core wire is pressed to the crimping portion so as to be plastically deformed in the extending direction of the electric wire. Then, the oxide layer formed on the surface of the core wire rubs against opening edges of the recesses and removed therefrom. Then, the surface of the core wire emerges and comes into contact with the crimping portion. This reduces a contact resistance between the electric wire and the terminal connector. [Patent Document 1] Japanese Unexamined Patent Publication No. JP-10-125362
Recently, it has been considered that aluminum or aluminum alloy is used as a material of the core wire. The oxide layer is comparatively easily formed on a surface of aluminum or aluminum alloy. Therefore, if aluminum or aluminum alloy is used for the core wire of the electric wire, a contact resistance between the core wire and the crimping portion may not be sufficiently reduced even if the recesses are formed.
It is thought that a plurality of recesses are aligned along the extending direction of the electric wire and also aligned along a crossing direction crossing to the extending direction of the electric wire. Accordingly, a total area of the opening edges of the recesses is increased compared to a case in which the recesses are aligned only in the extending direction of the electric wire. Therefore, it is expected that the oxide layer formed on the core wire is surely removed.
However, according to the above configuration, manufacturing cost of the die for forming the recesses may be increased due to the following reason. Protruding parts are formed at positions in the die so as to correspond to the recesses. The protruding parts are formed by cutting a metal plate material. At this time, there may be occurred a case in that the metal plate material should be cut by electro-discharge machining according to the arrangement of the recesses. This increases manufacturing cost of the die.
Therefore, there is a need in the art to provide a terminal connector and an electric wire with a terminal connector that reduces a contact resistance with the electric wire and reduces manufacturing cost of a die.